APPLICATION OF SPECIAL TECHNIQUES IN THE CONSTRUCTION OF THE MRAZOVKA TUNNEL IN PRAGUE

摘要

The construction of the Mrazovka Tunnel is executed in difficult geological conditions, with variable overburden and in its central section under a built-up area. To ensure necessary rock mass stability, to increase the rock stiffness, to strengthen tunnel overburden and to keep contractual deformation parameters, additional special techniques were applied - strengthening and compensation grouting and micropile umbrellas executed by the BOODEX technique.